A variety of cameras, film cassettes, bulk film containers and the like are sold preloaded with a long, relatively narrow filmstrip formed into a cylindrical film roll. (The terms "film" and "filmstrip" are used herein to refer to the same physical article. "Film" is used as the more general term. "Filmstrip" is used where it is desired to emphasize that the film, when unrolled, has the form of a long, narrow rectangle. The term "film supply" is used to refer to the camera, cassette, or container that holds the filmstrip. The roll of film is, in many cases, wound around a central spool or core. In other cases, the core is deleted in an effort to reduce expense, complexity, and weight and the film is in the form of a coreless scroll or "roll". In some cases, such as one-time use cameras, a film spool is attached to the free end. The film spool can be enclosed within a canister.
A number of approaches have been followed in loading and prewinding film rolls in one-time use cameras and other housings. In some approaches, such as one taught in U.S. Pat. No. 4,972,649; film is prewound into a roll outside a camera body and then loaded. A shortcoming of these approaches is that the film roll must be handled after it is formed. This presents a risk of film damage and may add complexity to necessary equipment. In some other approaches, also taught in U.S. Pat. No. 4,972,649; the cartridge is loaded, the camera is light-tightly closed, and the film is then prewound. In still other approaches, such as taught by U.S. Pat. No. 5,311,231; the cartridge is loaded and then the rear opening of the camera body is closed and the film is prewound on a shaft extended into the camera through a bottom opening, which is later sealed. The latter two approaches have the shortcoming that film guiding is provided primarily by the camera body, rather than loading apparatus. This places constraints on the camera body in terms of required tolerances and the like and may, in addition, slow throughput speeds. Similar shortcomings are presented by U.S. Pat. No. 1,921,559 and U.S. Pat. No. 1,921,560 which teach thrust cartridge cameras which prewind to an empty roll chamber having generally concave walls. Still another approach is taught by Japanese Kokai 6-295022, European Patent Application No. 0743546-A, and Japanese Kokai 8-171180. In this approach, the film is wound onto a second spool, rather than being wound into a film roll. The back of the camera is not mandatory for guiding the film, since the second spool tends to restrain the film.
A prevalent shortcoming of these approaches is that one or both surfaces of the film are subject to frictional contact during the film loading process. For example, such frictional contact is likely in U.S. Pat. No. 5,311,231, when the shaft is driven backward after the film roll has been formed to cause the film roll to clockspring and release the shaft.
It would thus be desirable to provide a film loading apparatus, and method, and a camera frame assembly suitable for use therewith, in which loaded film is protected from frictional contact during film loading, except along longitudinal edges spaced from the image area of the film.